Interrupter for ignition devices



0ST. MASON. INTERRUPTER FOR IGNITION DEVICES.

APPLICATION FILED APR.2,1918.

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Patented Aug. 16, 1921.

2 SHEETS-SHEET 2- Svvuamtoz UNITED STATES PATENT OFFICE.

CHARLES THOMAS MASON, 0F SUMTER, SOUTH CAROLINA, ASSIGNOR TO SPLITDORFELECTRICAL COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

INTERRUPTER FOR IGNITION DEVICES.

Specification of Letters Patent.

Patented Aug. 16, 1921.

Application filed April 2, 1918. Serial No. 226,292.

To all whom it may concern Be it known that I, CHARLES THOMAS MASON, acitizen of the United States, residing at Sumter, in the county ofSumter and State of South Carolina, have invented certain new and usefulImprovements in Interrupters for Ignition Devices, of which thefollowing is a specification, reference being had to the accompanyingdrawing.

The invention relates to new and useful improvements in interrupters forignition devices and more particularly to an interrupter for breakingthe primary circuit in a high tension ignition system for producing acurrent in a secondary circuit for sparking purposes. In my copendingapplication, Serial No. 223,164, filed March 18th, 1918, I have shownand described a method and ignition mechanism for carrying out themethod in which the primary circuit of a high tension ignition system isinterrupted by the separation of the same pair of contacts at eachsparking interval and wherein the resistance of said contacts whenclosed is reduced by other contacts arranged in multiple therewith andwhich are timed so as to open before and close after the other contactswhich interrupt the primary circuit.

An object of the present invention is to provide an interrupter for anignition systern such as set forth in my prior application, whichinterrupter is so constructed and operated that the contacts forreducing the resistance through the contacts which oper ate to make andbreakthe circuit have a rubbing engagement with each other in order tomaintain a clean metal surface contact engagement between said contacts.

'A further object of. the invention is to provide an interrupter of theabove charac ter wherein both of the movable contacts are yieldinglycarried by an interrupter lever and wherein the movement of one of saidcontacts is positively limited.

These and other objects will in part be obvious and will in part behereinafter more fully disclosed. y

In the drawings which show by way of illustration, one embodiment of theinvention:

Figure 1 is an end view of a magneto generator having my improvedinterrupter attached thereto, the cover plate being removed;

Fig. 2 is a view partly in side elevation and partly in vertical sectionthrough the game, the section being on the line 2-2 of Fig. 3 is adetail view the interrupter supporting block;

Fig. 4 is a sectional view on the line M of Fig. 3, showing both pairsof contacts in engagement so that the current in the magneto may buildup to maximum efficiency;

Fig. 5 is a similar view but showing the pair of contacts of relativelyhigh conductivity as separated preparatory to the separating of thecontacts of relatively low conductivity for producing a spark;

Fig. 6 is a similar view pairs of contacts separated;

Fig. 7 is a view showing more or less diagrammatically the interrupterlever, the cam for operating the same and the fixed contacts and at thetime when the contacts of relatively high conductivity are first broughtinto enga ement;

Fig. 8 is asimi ar view but showing the cam as having completelyreleased the in terrupter lever and the contacts as having slid or movedtransversely on each other for cleaning the surfaces thereof.

The invention is embodied broadly in an interrupter for breaking thecircuit of a high tension ignition system which includes two pairs ofcontacts, one of which is of higher conductivity than the other. Onecontact in each pair is fixed while the other contacts of each pair arecarried by a movable lever which is operated by a cam on the main Shaftof the magneto or generator, when the interrupter is applied to suchignition system. Both of the contacts carried by the lever are mountedyieldingly thereon, preferably by attaching each contact to a flatspring arm. The arms are'independently yieldable. limiting the movementof the spring arm carrying the contact of relatively highconductivity,so as to insure that these contacts will be pressed firmly together bythe spring means which shifts the lever. This spring arm which carriesthe movable contact of relatively high conductivity is so disposed onsaid lever and relative to the fulcrum of the lever that the contactswill have a rubbing engagement with each other so as but showing bothMeans is also provided for to keep the metal surfaces clean which makecontact. It is well understood that where a spark passes from onecontact to another the spark tends to maintain the metal surface of thecontacts clean but where there is no spark there is liable to be more orless accumulation which tends to create a resistance between the metalsurface of the contacts. By this rubbing of the metal surfaces of thecontacts which do not spark am able to keep the surfaces clean and thusthe resistance due to these contacts at a minimum.

Referring more in detail to the drawings, I have shown my invention asapplied to an interrupter for a magneto which is indicated at M in thedrawings. The main shaft of the magneto is indicated at 1. Theinterrupter includes two pairs of contacts, one pair is indicated at 2and 3 while the other pair is indicated at 4 and 5. The contacts 2 and 3are preferably formed of tungsten or similar metal of relatively lowconductivity. lit is understood that metal contacts of this characterare not injured or damaged by sparking but that the resistance in theprimary circuit of the generator or magneto will be considerablyincreased by the use of contacts of this type. The concontacts 4 and 5are preferably of silver or some other metal of relatively highconductivity. These contacts are not used to make and break the circuitfor causing a spark in the secondary winding of the ignition system butare used for reducing the resistance in the primary circuit afforded bythe contacts 2 and 3 of relatively low conductivity. To this end thesecontacts 1 and 5 are timed so as to open before and close after thecontacts 2 and 3. The contacts 2 and 1 are relatively fixed. Thesecontacts are carried by an L-shaped block 6 which sets in a recess 7 inthe base 8 which supports the interrupter parts. Said block 6 isinsulated from the base by means of an insulating strip 9. The block issecured to the base by screws 10 which are also insulated from the base8. The primary circuit is connected to this block 6 by a wire 11extending through a slot in the base 8. The cap for incloslng the partsof the interrupter in indicated at C. The contact 4 is formed as part ofa screw 12 which is threaded into the block 6 and is capable ofadjustment therein and is held in adjusted positions by a lock nut 13.The contact 2 is carried by a similar screw 14 which is locked inadjusted positions by a lock nut 15.

The contacts 3 and interrupter lever 16. This interrupter lever 16 ispivoted at 17 and is moved in one direction by a spring 18 attached toan abutment 19 carried by the base 8 and at its other end to theinterrupterlever 16. This 5 are supported by the.

interrupter lever 16 may be made of any suitable construction but asherein shown it is formed from sheet metal stamped into channel shape.In my co-pending application, Serial No. 225,030 filed March 27th, 1918,I have shown an interrupter lever similar in construction to that hereinshown and also mounted in a similar manner and have claimed suchspecific mounting and, therefore, further detailed description of theconstruction and mounting of the present interrupter lever will not benecessary. It is understood, however, that in certain aspects of theinvention this lever may be of any idesired construction.

Mounted on the lever 16 is a fiber block 19 which cooperates with a cam20 on the shaft 1. This cam 20 is concentric throughout a greaterportion of its extent but is provided with a flat face 21. As the camrotates the interrupter lever will be swung on its fulcrum point so asto move the contacts away from each other and said lever is. returned tocause the contacts to close by the spring 18, when the fiat side of thecam moves underneath the fiber block 19'. As herein shown, the movablecontact 3 is carried by a spring arm 22. While the movable contact 5 iscarried by a spring arm 23 these spring arms are shown as formed fromthe same piece of metal and as secured to the lever by screws 21-24. Theinterrupter lever is formed with an opening 25 for each movable contact.The contacts are preferably screwed or riveted to the spring arms: Theopening 25 is slightly larger in diameter than the contacts andparticularly larger in diameter than the contact 5. The lever is formedwith a bent up portion 26 which overhangs the end of 105 the arm 23. Theoverhanging portion 26 is placed above the arm 23 so asto permit alimited movement thereof.

When the parts are in the position shown in Fig. 8, both contacts areclosed. The 1 spring arm 23 is raised sli htly from the upper face ofthe lever 16. he spring arm 22 is raised therefrom to a greater extent.The overhangin portion 26 engaging the arm 23 limits t e movement of t einter- 115 rupter lever toward the cam so that these contacted and 5 arepressed into engagement with each other by the full force of the sprin18. When 1: e parts are in the position s own in Fig. 8, the spring armis 120 raised from the lever 16 to a greater distance than the springarm 23, substantially twice the distance. As the cam 21 rotates theinterrupter lever will be raised and will first engage the arm 23 andseparate the con- 125 taots 1 and 5, as clearl shown in Fig. 5 of thedrawings. A furt er movement of the interrupter lever 16 in an upwarddirection separates the contacts 2 and 3 and breaks the primary circuitfor producing the igni- 130 tion spark. A continued movement of the camwill finally cause the lever 16 to be lowered through the action of thespring 18 and the contacts 2 and 3 will close first, as is obvious fromFig. 6 of the drawings. A further downward movement of this lever 16will close the contacts 4t and 5. When these contacts close inasmuch asboth pairs of contacts are in multiple the resistance offered to theprimary circuit through the tungsten contacts 2 and 3 will be greatlyreduced. In Fig. 7 I have shown the position of the parts when thecontacts 4 and 5 are first brought into engagement. In Fig. 8 I haveshown the lever 16 as moving still further ina downward direction andthe movement of said lever limited by the overhanging portion 26. Itwill be noted that when the parts move from the position shown in Fi 7.to the position shown in F 1g. 8, the

ines 0;, h, and b, c, tend to straighten outor to approach the line a,c. In other words, the point 6 continues to move about the fulcrumof'the lever as a center while the point 0 cannot move further in adownward direction as the contacts are in engagement. The result is thatthe point 0 moves to the right and this causes the movable contact afterit has engaged the fixed contact torub or slide thereon laterally asindicated in Fig. 8. This rubbing action between the contacts cleans themetal surfaces and maintains an efficient electrical engagement betweenthe contacts thus reducing to a minimum the resistance in the primarycircuit. As the lever starts to move in an upward direction the contactswill slide again on each other to the position shown in Fig. 7 and thenthe movable contact will be-directly raised from engagement with thefixed contact.

. It will be understood, of course, that changes in the details ofconstruction may be made without departing from the spirit of theinvention which consists broadly in the pairs of contacts in multiplewherein the breaking of the circuit for producing the spark is producedat all times on one pair of contacts while the other air opens beforeand closes after the pair of contacts breaking the circuit and whereinthe contacts which do not break the circuit for sparking purposes, havea rubbing action one on the other to maintain the surfaces thereof cleanand free from accumulation which might tend to resist the building up ofthe maximum current in the generator.

Attention is further called to the fact that by my improved constructiondescribed above, the movable contacts may be readily removed by takingout the screws 24 without removing the interrupter lever. Then again, itis noted that the connection from the primary to the stationary contactsis wholly within the cap inclosing the parts of the interrupter.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. An interrupter mechanism for ignition systems, comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxlliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, means for supporting and operating said contacts whereby saidauxiliary contacts are caused to rub one on the other after they are inengagement.

2. An interrupter mechanism for ignition systems, comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, an interrupter lever for said contacts and means forsupporting the movable con tacts thereon whereby the auxiliary contactsare caused to rub one on the other after they are in engagement.

3. An interrupter mechanism for ignition systems, comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, an interrupter lever for supporting the movable contacts,spring arms carried by the interrupter lever, one for each movablecontact, said cfontacts being disposed on said spring arms so that themain contacts will open after the auxiliary contacts and close beforesaid auxiliary contacts.

4:. An interrupter mechanism for ignition systems, comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pa r of auxiliary contacts in multiplewlth said main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, an, interrupter lever for supporting the movable contacts,spring armscarried by the interrupter lever, one for each movablecontact, said contacts being disposed on sa d spring arms so that themain contacts Wlll open after the auxiliary contacts and close beforesaid auxiliary contacts, said spring arms being also disposed so thatthe auxiliary contacts will rub one on the other after they are inengagement.

5. An interrupter mechanism for ignition systems, comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, an interrupter lever, a cam for moving the interrupter leverin one direction, a spring for moving it in the other direction, springarms mounted on said interrupter lever and carrying the movablecontacts, said arms and contacts being disposed so that the maincontacts will open after and close before the auxiliary contacts andsaid auxiliary contacts will be caused to rub one on the other afterthey are in engagement.

'6. An interrupter mechanism for ignition systems, comprising a pair ofmain contact-s one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts one of which is movable, said auxiliary contactsbeing timed so as to open before and close after said main contacts, aninterrupter lever, a cam for moving said lever in one direction and aspring for moving the lever to cause the contacts to close, spring armscarried by the lever and carrying said contacts said spring arms beingmounted adjacent the fulcrum of the lever and extending outwardly on thelever, means carried by the lever and overhanging the spring armcarrying the auxiliary contact for limiting the movement of the springarm.

7. An interrupter mechanism for ignition systems comprising a fixedcontact, a pivoted lever, a flat spring attached to said lever on theside thereof opposite the fixed contact, said lever having an openingtherethrough, a contact carried by said flat spring, projecting throughthe opening in the lever and adapted to engage the fixed contact, and acam for engaging the lever for moving said lever to cause said spring toseparate the contacts, said lever being movable toward the fixed contactafter said contacts are in engagement for causing a sliding of onecontact on the other.

8. An interrupter mechanism for ignition systems comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed to open before and close after the main contacts,an interrupter lever carrying the movable contacts, means for operatingthe lever, a fiat spring detachably connected to the outer face of thelever and, extending lengthwise thereof, said movable contacts beingcarried by said flat spring.

9. An interrupter mechanism for ignition systems comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith said main contacts and one of which is movable, said auxiliarycontacts being timed to open before and close after the main contacts,an interrupter lever carrying the movable contacts, means for operatingthe lever, a flat spring detachably connected to said lever and havingtwo independent arms on which the movable contacts are mountedrespectively, said lever having openings through which the contactsextend for engagement with the fixed contacts.

10. An interrupter mechanism for ignition systems comprising a pair ofmain contacts one of which is movable for breaking a circuit forproducing an ignition spark, a pair of auxiliary contacts in multiplewith the main contacts and one of which is movable, said auxiliarycontacts being timed so as to open before and close after said maincontacts, a supporting base, an interrupter lever mounted on the baseand carrying the mov able contacts, means for operating the interrupterlever, an L-shaped block secured to but insulated from said base andcarrying the fixed contacts.

CHARLES THOMAS MASON.

